Social and ethnic inequalities in the offer and uptake of prenatal screening and diagnosis in the UK: a systematic review
Introduction
Prenatal screening programmes provide information to increase the likelihood of identifying important conditions in the mother or the fetus before birth, and to enable pregnant women and their partners to make an early and informed choice about the options available to them. These include undergoing further testing to become certain of the diagnosis, receiving treatment if effective treatment exists, preparing for the birth of an affected child or terminating the pregnancy.
Screening is a substantial component of antenatal care in the UK and screening policy is subject to continual review (see National Electronic Library for Health website: http://www.nelh.nhs.uk/screening/antenatal_pps/antenatal.html). At the time of writing, screening for maternal conditions such as susceptibility to rubella or infection with syphilis is carried out routinely on all women. Some other screening tests, such as screening for maternal hepatitis B and biochemical screening for neural tube defects or Down's syndrome, should be offered to all pregnant women. There are also a number of additional prenatal screening tests that may be offered to targeted populations at increased risk for particular conditions. Examples of these include genetic screening for inherited conditions such as Tay-Sachs disease and the haemoglobinopathies. Where a screening test identifies a woman to be at high risk of abnormality, prenatal diagnosis is then offered to ascertain whether the pregnancy is affected.
The absence of local and national policies on screening have led to wide regional variation in the tests offered to women for Down's syndrome, and in the availability of screening for the haemoglobinopathies.1., 2.
Alongside geographic variability in the availability of prenatal screening, it is also hypothesized that social inequalities exist in access to screening. There is some evidence, for example, that women from lower social classes and from some ethnic groups are less likely to receive screening for breast and cervical cancer. Regional health authority and health district data on uptake and coverage of cervical and breast screening point to a lower coverage of these screening programmes in wards with higher Townsend deprivation scores.3 National surveys also show an individual social class gradient for cervical smear and breast screening uptake.3
Similar systematic social inequalities in access to, or differences in the uptake of, prenatal screening would have significant implications for women at higher risk of the conditions for which screening is available and for national screening strategies. Some of the conditions screened for in pregnancy are themselves more prevalent in women from population subgroups that are also more likely to be disadvantaged. HIV is more prevalent in women of African origin than in European women. Women of Afro-Caribbean and West African origin are genetically most at risk of sickle cell diseases, while thalassaemia is more prevalent in women of Cypriot, South Asian and Chinese origin. Reduced access to screening for women at higher risk of these conditions would further increase the chances of giving birth to an affected baby. The associated physical, emotional and financial costs could compound any disadvantage already experienced by families in these subgroups.
A recent systematic review examining the determinants of screening uptake and interventions for increasing uptake across a wide range of screening tests did not include studies on prenatal screening.4 The objective of the present study was to review UK studies assessing rates of prenatal screening according to social class or ethnic origin.
This review considered two possible routes by which social inequalities in prenatal screening coverage might arise. Women from certain social classes or ethnic groups may be less likely to be offered screening, and certain women may be less likely to take up screening when offered. Social inequalities in the offer of screening would clearly require very different remedies from inequalities in the acceptance of screening. For this reason, studies in this review were assessed in terms of utilization, the number of women screened as a percentage of those eligible; offer, the number of women offered screening as a percentage of those eligible; and uptake, the number of women screened as a percentage of those offered screening.5
Inequalities in prenatal screening might also occur by inadequate provision of a screening programme for disorders only affecting ethnic minority populations, such as the haemoglobinopathies, but this was outside the scope of this review.
Section snippets
Inclusion criteria
The review included UK studies published after 1979 that assessed the provision, utilization or uptake of prenatal screening or diagnostic tests for pregnant women according to any measure of social class or ethnic group. Studies reporting only on women's intention to have prenatal screening were excluded.
Search methods
A range of electronic databases were searched using terms drawn from a search strategy for a wider review of inequalities in access to maternity care, supplemented with terms specific to
Results of the literature search
The searches identified over 600 papers. Of these, 41 appeared to be potentially relevant. Nineteen studies, reported in 20 papers, met the inclusion criteria. Of the 21 excluded papers, 14 reported no data comparing offer or uptake of screening according to social class or ethnicity, or reported only on other aspects of screening, such as knowledge, without providing data on offer or uptake. One study reported only on women's intention to have prenatal screening. The remaining six excluded
Discussion
The findings of these studies were mixed and did not present a consistent pattern across different types of screening. Within screening tests, there was more agreement between study findings, suggesting that women from some ethnic groups are less likely to receive prenatal testing for certain conditions. Knowing whether women receive screening, however, is of only limited usefulness in establishing whether significant social inequalities exist in women's access to screening. We were also
Conclusions
This review provides evidence that women from some ethnic groups, particularly South Asian women, may be less likely to receive prenatal diagnosis for haemoglobin disorders and Down's syndrome. The studies reviewed here suggest that significant proportions of South Asian women will take up prenatal testing if offered, but that these women may be less likely to be offered testing. The findings of this review point to the need for a systematic approach to identifying the factors associated with
Acknowledgements
This study was funded by the Community Fund (formerly the National Lottery Charities Board) and the Department of Health. None of the authors are aware of any conflict of interest.
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